Device for the supply of a gas

ABSTRACT

A device for supply of a gas to a volume includes a supply conduit, which is connectable to a gas source and which includes an outlet end, and a porous body, which is provided at the outlet end. The device is arranged to permit the supply of the gas through the porous body. The device includes an attachment member which includes a surface and a channel extending through the surface. The porous body is attached to the surface and the outlet end is connected to the attachment member in order to permit the supply via the channel.

THE BACKGROUND OF THE INVENTION AND PRIOR ART

The present invention refers to a device for the supply of a gasaccording to the precharacterising portion of claim 1. Such a device isdisclosed in the previous application of the applicant, WO01/45790.

During surgery, which is performed in an open manner, i.e. when an innerportion of the body is uncovered for the performance of the surgicaloperation, it can be important to prevent air from the surroundings toreach the open portion of the body in order to avoid infections, forinstance. Such infections may be caused by microorganisms and bacteria,which are always present in the surrounding air and which fall downtowards the open portion of the body. It is thus desirable to create aprotecting atmosphere around the open portion in order to protect saidinner portion from non-sterile air and also falling particles. Inaddition, different surgical operations may involve various requirementson the protecting atmosphere. In this connection it is referred toWO01/45790, which discloses the supply of a gas for the formation ofsuch an atmosphere.

In order to create such a protecting atmosphere around, for instance, atemporary open, inner portion of a human being, it is important to avoidthe formation of turbulence in the supplied gas volume, which shouldform the protecting atmosphere, since the turbulence may involve mixingof air from the surroundings in the gas volume. WO01/45790 proposes theuse of a foam rubber body for the supply of a gas with a controlledlaminar flow at an extremely low flow velocity from the surface of theporous foam rubber body.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a device for thesupply of a gas to an area. Especially, it is aimed at such a device forcreating a protecting gas atmosphere in said area or in a cavity. Suchan area may for instance adjoin an outwardly open, inner portion of thebody of a human being or an animal.

This object is obtained by the device initially defined, which ischaracterised in that it includes an attachment member, which includes asurface and a channel extending through the surface, wherein the porousbody is attached to said surface and wherein the outlet end is connectedto the attachment member for permitting said supply via said channel.

Such a device is suitable for the supply of gas in several differentcontexts in the medical services or industry in order to create a cleanprotecting gas atmosphere. A plurality of different gases may besupplied by the device, for instance carbon dioxide, oxygen gas, air,nitrogen gas, etc.

By such an attachment member, a sufficiently large surface may becreated for attaching the porous body in a secure manner. Furthermore,the porous body will be kept stretched during use so that unintentionaltotal compression thereof is made significantly more difficult. However,it is also possible to manually compress the porous body by pressing itaxially towards the surface of the attachment member and in such a waypress out a liquid, for instance blood, from the porous body. A largequantity of liquid in the body may deteriorate its capability ofproviding a laminar gas flow. By such an attachment member, also theoutflow direction or outflow directions of the gas supplied through theporous body will be guided, for instance to flow outwardly from the bodyforwardly and laterally. A rearward flow may for instance be preventedin an efficient manner. By such an attachment member, also lessturbulence may be obtained in the volume to which the gas is supplied.The attachment member and the porous body may be manufactured with smalldimensions and thus be provided very close to or in said area.

According to an embodiment of the invention, said surface of theattachment member covers substantially the whole porous body seen in afirst direction extending from the attachment member through the body.In such a way, gas is efficiently prevented from flowing rearwardly fromthe porous body. However, the surface may also have a smaller extensionand permit a certain rearward flow.

According to a further embodiment of the invention, the attachmentmember includes a sleeve, which extends outwardly away from the porousbody and which is connected to the outlet end, wherein the channelextends through the sleeve. The sleeve may advantageously extend in adirection forming an angle to the first direction, wherein said angle is0 to 90°. Either the supply conduit projects into the sleeve or thesleeve projects into the supply conduit.

According to a further embodiment of the invention, the attachmentmember and the porous body are substantially circular seen in the firstdirection. Such a shape is uniform and secures a uniform flow in alldirections extending radially from the first direction. Furthermore, theporous body may have a substantially semi-spherical surface which facesaway from the attachment member. In such a way also a uniform flow inall directions forwardly, i.e. with a component in the first direction,is ensured.

According to a further embodiment of the invention, the supply conduitincludes at least a first conduit portion with a casing of a material,which has a large flexibility, and with a means for stiffening, whichextends along the casing and has a lower flexibility than the casing. Bymeans of such a construction, a large bendability of the supply conduitis obtained in such a way that it may be bent to any shape permittingthe body to be positioned in a advantageous manner in said volume.Furthermore, the stiffening means permits the supply conduit to maintainthe shape obtained during use of the device. Thus the stiffening meansmay be plastically deformable and may for instance include a metal wire.Furthermore, the stiffening means may advantageously extendsubstantially freely within the supply conduit and more precisely withinthe first conduit portion.

According to a further embodiment of the invention, the porous body ismanufactured of a foam rubber-like material. Such a material has a lowweight and is therefore easy to handle in sensible environments. Foamrubber materials are also inexpensive. Advantageously, the foamrubber-like material includes polyurethane foam with a very largequantity of adjacent, small open cells, which may function as supplynozzles for the gas. The porous body may also be manufactured of apermeable material including at least one of paper, felt, sinter metaland filter material. Furthermore, the porous body may include ahomogenous body, for instance with regard to the porous material beingsubstantially uniform with a substantially uniform cell size in thewhole body. However, it is also possible to let the body have an innerlarger cavity defining an inner surface of a wall, wherein the gas flowsinto the cavity through the porous wall of the body. The outer shape ofthe body may be homogenous in the sense that the surface issubstantially uniform, as in the above-mentioned substantiallysemi-spherical shape or a spherical or more oblong shape.

According to a further embodiment of the invention, the device includesa filter, which is arranged on the supply conduit for filtering of saidgas flowing through the supply conduit. By means of such filter, the gasto be supplied may be purified from particles and microorganisms.

According to a further embodiment of the invention, said gas includes amain component which is carbon dioxide. Carbon dioxide has a higherdensity than air and will therefore sink downwardly and form a gascushion at or above said area. Carbon dioxide has several medicaladvantages, which appear from the previous application of the applicant,WO99/29249. The gas may also be a mixture of one or several maincomponents, such as carbon dioxide and/or oxygen, and differentadditional components, such as steam, disinfectants, sterilisingsubstances, inclusive alcohol, solved medicaments, includinganticoagulants, antibiotic, hormones, tissue factors etc.

According to a further embodiment of the invention, the porous body isarranged to supply said gas in a controlled flow in order to enable theformation of a gas cushion, which is intended to substantially fill avolume at said area and thus to prevent air from the surroundings toreach said area. Said area may advantageously adjoin an inner portion ofthe body of a human being or an animal, which portion is open outwardlytowards the surroundings, wherein the porous body is arranged to belocated at said outwardly open inner portion.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is now to be described more closely by means of differentembodiments and with reference to the drawings attached.

FIG. 1 discloses schematically a view of a device according to anembodiment of the invention.

FIG. 2 discloses a view of a body of the device in FIG. 1.

FIG. 3 discloses a part of the device according to a second embodimentof the invention.

DETAILED DESCRIPTION OF DIFFERENT EMBODIMENT OF THE INVENTION

FIGS. 1 and 2 disclose a device according to a first embodiment of theinvention. The device disclosed is intended to create a protectingatmosphere in an area which here is exemplified by a concave volume Vadjoining a temporary open, inner portion P of a human being in order toprevent air from the surroundings from reaching the volume V. It is tobe noted that the area and thus the inner portion P also may besubstantially plane or even slightly convex. Such an open portion P isformed during operations performed in an open manner, i.e. when an innerportion P of the body is uncovered for the performance of the surgicaloperation. In connection with for instance heart surgery, a substantialpart of the interior of the thorax is uncovered so that this normallyhas direct contact with the surrounding atmosphere, i.e. with air.However, it is to be noted that the device according to the inventionmay be applied in many different contexts for the supply of gas tovarious volumes V. The device is designed in such a way that it permitsa controlled gas supply substantially without turbulence, which has theadvantage that if the supplied gas is heavier than air the gas may forma continuous gas cushion, which remains at the area.

The device includes a supply conduit 1 with an inlet end, which isconnectable to a gas source 2, for instance in form of a conventionalpressurised gas container. According to a preferred application of theinvention, the gas source 2 contains a gas which consists substantiallyof pure carbon dioxide or has a main component consisting of carbondioxide. The gas may also contain various additional components in formof gases, liquids or particles, for instance disinfectant gases. It isalso possible to let the gas contain various medicaments, which may besupplied to a patient by means of the device via the open portion P. Thesupply conduit 1 also has an outlet end. Furthermore, the deviceincludes a porous body 3, which is arranged at the outlet end. The gasis arranged to be supplied to the volume V through the supply conduit 1and the porous body 3 in a controlled flow in order to enable theformation of a gas cushion, which is intended to substantially fill saidvolume V. Air, particles and micro-organisms from the surroundings arethus prevented from reaching the volume V.

The device may be connected to or include a control valve 4 by means ofwhich the gas supply to the porous body 3 is controllable. In theexample disclosed, the control valve 4 is controlled by means of acontrol unit 5 connected to the control valve 4. The control unit 5 mayin its turn be connected to a gas sensor 6, which is arranged to sensethe concentration of for instance the gas supplied or air in the volumeV concerned. By means of such a sensing, the gas supplied to the volumeV may be controlled in such a way that if an increased air concentrationis detected, also the gas supply is increased, or if the airconcentration in the volume V exceeds a predetermined level the gassupply is increased.

The device may also include a humidifying member 7, which is connectedto the supply conduit 1 and which permits humidification of the gas tobe supplied with water or steam. In such a way, drying of the tissue inthe open portion P may be prevented. Furthermore, the device may includea cooling member and/or a heating member 8, which may be providedupstream and/or downstream the humidifying member 7 and which permitscooling of the gas to be supplied to a temperature which is somewhatlower than the temperature of the surrounding atmosphere. The coolinghas the advantage that the gas thanks to its lower temperature is givena higher density and consequently becomes heavier. In such a way, thegas may more easily displace the surrounding air in the volume Vconcerned. Cooling of surfaces, for instance an operation wound, may besped up, partly by the supply of the cooled gas with a homogenouslaminar flow by means of the cooling member 8 and partly by the factthat the supplied gas or gas mixture is not humidified. Thus theevaporation from the surface is promoted more than normally, which leadsto a cooling. In this manner, the temperature and the perfusion of bloodof a tissue during a limited time may be significantly reduced.

A skin surface, a wound surface or a wound volume exposed to thesurrounding air cools the patient not only locally at the surface butalso the whole body of the patient. The supply of a heated gas by meansof a heating member 8 to the exposed surface or volume will have anisolating or heating effect to the surface or the volume against such acooling. The cooling of an exposed surface is caused for instance of theevaporation of liquid from the surface. Since the gas is saturated withmoisture by means of the humidifying member 7 the surface is isolatedfrom the cooling evaporation since no liquid absorption from the surfaceto the supplied gas may take place. Since the evaporation and thecooling of a body surface or an operation wound in this way isprevented, the perfusion of blood will be higher than if the evaporationand cooling of the portions mentioned above take place. The device mayinclude a supply member 9 for the supply of the additional componentsmentioned above. Furthermore, the device includes a filter 10, which isarranged on the supply conduit 1 for filtering of said gas flowingthrough the supply conduit 1.

The porous body 3 may be manufactured of a foam rubber-like materialhaving a large number of open cells, which distributes the gas flow fromthe supply conduit 1 homogeneously in the porous body 3 so that the gasflow is distributed uniformly over its surface. This leads to lowoutflow velocities despite a very high inflow velocity from the supplyconduit 1. The cells, which lie very close to each other, thus functionas multiple supply nozzles, which permit the gas leaving the porous bodyto form a substantially laminar, continuous slow gas flow enabling theformation of the gas cushion. The porous body 3 is in the embodimentdisclosed totally manufactured of said foam rubber-like material andthus forms a homogenous foam-rubber body 3. Such a suitable material isfor instance polyurethane foam with open cells and with a density ofbetween for instance 20 and 40 kg/M³. The porous body 3 may also includeor consist of other materials than foam rubber materials, for instanceporous sintered plastics and other porous permeable materials, forinstance of paper, felt, sinter metal and/or filter material.

The device includes an attachment member 15, which is provided adjacentto the porous body 3. The attachment member 15 is in the embodimentdisclosed shaped as a substantially plane plate with a first surface 15′and a second opposite surface 15″, see FIG. 2. In the embodimentdisclosed, the surfaces 15′, 15″ are substantially plane. It is to benoted, however, that the first surface 15′ may have another shape, forinstance a concave or convex shape. The first surface 15′ may forinstance be conical and thus permit at least a certain rearward flow.The shape of the first surface 15′ may thus be utilised for guiding theoutflow direction(s) of the gas. However, it is to be noted that thefirst surface 15′ is to be at least partly directed forwardly in aforward direction x. The first surface 15′ thus faces away from thesecond surface 15″. The second surface 15″ may have a substantiallyarbitrary shape. The attachment member 15 is manufactured in anysuitable material, for instance PVC plastics. The attachment member 15may also be manufactured of any other material of plastics, rubber ormetal. The attachment member 15 includes a channel 16, which extendsthrough said surfaces 15′, 15″ and through which the gas. is conveyed inthe first forward direction x into the porous body 3. The porous body 3is attached to the first surface 15′ in a suitable manner, for instancethrough melting, gluing or vulcanisation. Furthermore, the attachmentmember 15 includes a sleeve 17, which extends outwardly from the secondsurface 15″ and thus away from the porous body 3. The sleeve 17 may, asin the embodiment disclosed, extend substantially in parallel with thefirst forward direction x but also in any other direction. The channel16 extends thus through the tubular sleeve 17, which is connected to thefirst conduit portion 1′.

The supply conduit I includes a first conduit portion 1′, which in theembodiment disclosed extends between the filter 10 and the attachmentmember 15, and a second conduit portion 1″, which extends between thegas source 2 and the filter 10. It is to be noted that the filter 10 maybe provided in another position in relation to the arbitrary members 7,8 and 9. For instance, the filter 10 may be provided substantiallyimmediately downstream the gas source 2. The first conduit portion 1′includes and is defined by a casing in the form of a thin flexible hose.The casing is thus manufactured of a material with a large flexibility,for instance a rubber material or plastic material such as silicon andPVC. Furthermore, the supply conduit 1 includes a means for stiffeningin the form of a stiffening member 18, which extends along the firstconduit portion 1 and which has a lower flexibility than the casing. Thestiffening member 18 may be attached to one or both ends of the conduitportions 1′, for instance to the inner wall of the sleeve 17 and in thetransition between the filter 10 and the first conduit portion 1′. Thestiffening member 18 may also be freely provided in the conduit portion1′ or be attached along its inner or outer side. A further possibilityis that the stiffening member 18 is moulded in the wall of the conduitportion 1′. The stiffening member 18 is plastically deformable withoutany substantial elasticity. The stiffening member 18 thus has acapability of remaining in the shape to which it is bent.Advantageously, the stiffening member 18 may include or be manufacturedof a metal wire, for instance of stainless steel. In the embodimentsdisclosed, the stiffening member 18 extends within the first conduitportion 1′. The stiffening means may also be obtained by designing thecasing proper, for instance by a folding of the casing.

The second conduit portion 1″ may be formed of any thicker and stifferhose or rigid pipe. The different components, the valve 4, the supplymember 9, the cooling member 8, the humidifying member 7 and the filter10 are in the embodiments disclosed arranged on the second conduitportion 1″.

The outlet end of the supply conduit 1, which thus is included by thefirst conduit portion 1′, is connected to the attachment member 15, insuch a way that the gas supply may take place via the channel 16. In theembodiments disclosed the first conduit portion 1′ projects into thesleeve 17 and is connected to the inner wall of the channel 16, forinstance by melting, gluing or vulcanisation. However, it is to be notedthat it is also possible to connect the sleeve 17 to the outlet end ofthe supply conduit 1 by letting the sleeve 17 project into the firstconduit portion 1′, wherein the first conduit portion 1′ may beconnected to the outer wall of the sleeve 17 by any of theabove-mentioned methods melting, gluing or vulcanisation or by shrinkingthe first conduit 1′ onto the sleeve 17.

Preferably, but not necessarily, said surfaces 15′, 15″ of theattachment member 15 cover substantially the whole porous body 3 seen ina first direction x, which extends through the attachment member and thebody, and more precisely through the channel. In the embodimentsdisclosed, the attachment member 15 and the porous body 3 aresubstantially circular seen in the first direction x. This shape isadvantageous since it permits a uniform flow in all radial directions.However, it is possible to let the attachment member and the porous body3 have other cross-sectional shapes, for instance oval, rectangular orsquare shapes. In the embodiments disclosed in FIG. 1, the porous body 3has a substantially cylindrical shape extending from the first surfaceof the attachment member 15 in the first direction x. In the embodimentdisclosed in FIG. 3, the porous body 3 has a substantiallysemi-spherical shape with an outer semi-spherical surface facing awayfrom the first surface 15′ of the attachment member 15.

The invention is not limited to the embodiments disclosed but may bevaried and modified within the scope of the following claims. Forinstance, the porous body 3 may advantageously be heparinised either bythe measure a) that it is primarily during manufacturing coated with aheparinised surface, so-called heparin-coating b) that it just beforeuse is saturated with active heparin, c) that the gas used containsheparin and/or d) that blood or liquids, which possibly will come intocontact with the porous body 3, already are heparinised and thus bloodor liquids will not to the same extent be able to block the open cellsof the porous body 3.

In a further embodiment of the invention, the porous body 3 is arrangednot only to fill a volume with the gas supplied (such as a wound cavityor an open container) but in such a way that the gas will cover asurface lacking any cavity in order to a) prevent the falling down ofparticles including micro-organisms to the surface, b) prevent othergases, for instance air, from reaching the surface and/or c) coat thesurface with or exposing the surface to one or several gaseousadditional components such as steam, disinfectants, sterilisingsubstances including alcohol, and/or dissolved medicaments, includinganticoagulants, antibiotic, hormones, tissue factors, etc.

In a further embodiment of the invention, the porous body 3 is arrangedto supply gases for inhalation, for instance oxygen gas, in front of thenose and/or the mouth, or in the nose and/or the mouth, wherein forinstance oxygen gas or air form said main component. The porous body 3may be separate or combined with other inhalation aiding means, forinstance an oxygen mask. Therethrough an even more efficient supply ofinhalation gas with its possible additives may be enabled. Also in thiscase a thin supplying hose with a stiffening means 18 for fixing theposition and shape of the hose is advantageous. A separate porous bodymay for instance be attached by means of tape onto the patient or bearranged at any fixed holding structure, for instance of a microphoneheadset type. By such a supply system for oxygen gas one may in asufficient manner avoid contact irritation at the nose and mouth whichare sensible to pressure and/or heat and/or moisture. Furthermore, anefficient oxygen supply is obtained. A further advantage is that one mayavoid the use of a nose catheter or a mask in front of the mouth and thenose, which make the communication with the patient more difficult.

In a further embodiment of the invention, the device consists of morethan one porous body 3, which are arranged in parallel or series to thesupplying supply conduit or supply conduits. The invention may thusinclude one or several advantageously thin supplying hoses, and one orseveral porous bodies 3.

The invention enables local protection above a surface or a volumeagainst fire or chemical attacks, for instance oxidation from othersurrounding gases such as air. If the gas supplied is for instancecarbon dioxide, protection against these two types of attacks can beobtained. Because thereof otherwise flammable gases, additives, such asalcohol that is an disinfectant, are transported to a surface or avolume such as an operation wound since the main component of thesupplied carrier gas is the fire protecting and fire extinguishing gascarbon dioxide.

The invention may as has been mentioned above also be applied withinother fields.

The invention may also be applied within industry in order to create aclean gas atmosphere locally at a surface or in a cavity, for instanceduring mounting, soldering, packaging within the food industry andelectronic/computer industry. In this case different types of gases maybe used. In certain cases, inert gases of the type nitrogen gas may beadvantageous.

1. A device for the supply of a gas to an area, comprising: a supplyconduit, which is connectable to a gas source and which includes anoutlet end, and a porous body, which is provided at said outlet end,wherein the device is arranged to permit said supply of gas through theporous body, the device includes an attachment member, which includes asurface and a channel extending through the surface, wherein the porousbody is attached to said surface and wherein the outlet end is connectedto the attachment member for permitting said supply via said channel. 2.A device according to claim 1, wherein said surface of the attachmentmember covers substantially the whole porous body seen in a firstdirection extending from the attachment member through the body.
 3. Adevice according to claim 1, wherein the attachment member includes asleeve, which extends outwardly away from the porous body and which isconnected to the outlet end, wherein the channel extends through thesleeve.
 4. A device according to claim 2, wherein the sleeve extends ina direction forming an angle to the first direction (x), wherein saidangle is 0 to 90°.
 5. A device according to claim 3, wherein the supplyconduit projects into the sleeve, or that the sleeve projects into thesupply conduit.
 6. A device according to claim 2, wherein the attachmentmember and the porous body are substantially circular seen in the firstdirection (x).
 7. A device according to claim 6, wherein the porous bodyhas a substantially semispherical surface which faces away from theattachment member.
 8. A device according to claim 1, wherein the supplyconduit includes at least a first conduit portion with a casing of amaterial, which has a large flexibility, and with a means forstiffening, which extends along the casing and has a lower flexibilitythan the casing.
 9. A device according to claim 8, wherein thestiffening means is plastically deformable.
 10. A device according toclaim 8, wherein the stiffening means includes a metal wire.
 11. Adevice according to claim 8, wherein the stiffening means extendsubstantially freely within the first conduit portion of the supplyconduit.
 12. A device according to claim 1, wherein the porous body ismanufactured of a foam rubber-like material.
 13. A device according toclaim 12, wherein the foam rubber-like material includes polyurethanefoam with open cells.
 14. A device according to claim 1, wherein theporous body is manufactured of a permeable material including at leastone of paper, felt, sinter metal and filter material.
 15. A deviceaccording to claim 12, wherein the porous body includes a homogenousbody.
 16. A device according to claim 1, wherein the device includes afilter, which is arranged on the supply conduit for filtering said gasflowing through the supply conduit.
 17. A device according to claim 1,wherein said gas includes a main component which is carbon dioxide. 18.A device according to claim 1, wherein the porous body is arranged tosupply said gas in a control flow in order to enable deformation of agas cushion, which is intended to substantially fill a volume at saidarea and thus prevents air from the surroundings to reach said area. 19.A device according to claim 1, wherein said area adjoins an innerportion of the body of a human being or an animal, which portion is openoutwardly towards the surroundings, wherein the porous body is arrangedto be located at said outwardly open inner portion.